$.extend(jQuery.easing, {

	easeIn: function(x, t, b, c, d) { //加速曲线
		return c * (t /= d) * t + b;
	},
	easeOut: function(x, t, b, c, d) { //减速曲线
		return -c * (t /= d) * (t - 2) + b;
	},
	easeBoth: function(x, t, b, c, d) { //加速减速曲线
		if ((t /= d / 2) < 1) {
			return c / 2 * t * t + b;
		}
		return -c / 2 * ((--t) * (t - 2) - 1) + b;
	},
	easeInStrong: function(x, t, b, c, d) { //加加速曲线
		return c * (t /= d) * t * t * t + b;
	},
	easeOutStrong: function(x, t, b, c, d) { //减减速曲线
		return -c * ((t = t / d - 1) * t * t * t - 1) + b;
	},
	easeBothStrong: function(x, t, b, c, d) { //加加速减减速曲线
		if ((t /= d / 2) < 1) {
			return c / 2 * t * t * t * t + b;
		}
		return -c / 2 * ((t -= 2) * t * t * t - 2) + b;
	},
	elasticIn: function(x, t, b, c, d, a, p) { //正弦衰减曲线（弹动渐入）
		if (t === 0) {
			return b;
		}
		if ((t /= d) == 1) {
			return b + c;
		}
		if (!p) {
			p = d * 0.3;
		}
		if (!a || a < Math.abs(c)) {
			a = c;
			var s = p / 4;
		} else {
			var s = p / (2 * Math.PI) * Math.asin(c / a);
		}
		return -(a * Math.pow(2, 10 * (t -= 1)) * Math.sin((t * d - s) * (2 * Math.PI) / p)) + b;
	},
	elasticOut: function(x, t, b, c, d, a, p) { //正弦增强曲线（弹动渐出）
		if (t === 0) {
			return b;
		}
		if ((t /= d) == 1) {
			return b + c;
		}
		if (!p) {
			p = d * 0.3;
		}
		if (!a || a < Math.abs(c)) {
			a = c;
			var s = p / 4;
		} else {
			var s = p / (2 * Math.PI) * Math.asin(c / a);
		}
		return a * Math.pow(2, -10 * t) * Math.sin((t * d - s) * (2 * Math.PI) / p) + c + b;
	},
	elasticBoth: function(x, t, b, c, d, a, p) {
		if (t === 0) {
			return b;
		}
		if ((t /= d / 2) == 2) {
			return b + c;
		}
		if (!p) {
			p = d * (0.3 * 1.5);
		}
		if (!a || a < Math.abs(c)) {
			a = c;
			var s = p / 4;
		} else {
			var s = p / (2 * Math.PI) * Math.asin(c / a);
		}
		if (t < 1) {
			return -0.5 * (a * Math.pow(2, 10 * (t -= 1)) *
				Math.sin((t * d - s) * (2 * Math.PI) / p)) + b;
		}
		return a * Math.pow(2, -10 * (t -= 1)) *
			Math.sin((t * d - s) * (2 * Math.PI) / p) * 0.5 + c + b;
	},
	backIn: function(x, t, b, c, d, s) { //回退加速（回退渐入）
		if (typeof s == 'undefined') {
			s = 1.70158;
		}
		return c * (t /= d) * t * ((s + 1) * t - s) + b;
	},
	backOut: function(x, t, b, c, d, s) {
		if (typeof s == 'undefined') {
			s = 3.70158; //回缩的距离
		}
		return c * ((t = t / d - 1) * t * ((s + 1) * t + s) + 1) + b;
	},
	backBoth: function(x, t, b, c, d, s) {
		if (typeof s == 'undefined') {
			s = 1.70158;
		}
		if ((t /= d / 2) < 1) {
			return c / 2 * (t * t * (((s *= (1.525)) + 1) * t - s)) + b;
		}
		return c / 2 * ((t -= 2) * t * (((s *= (1.525)) + 1) * t + s) + 2) + b;
	},
	bounceIn: function(x, t, b, c, d) { //弹球减振（弹球渐出）
		return c - this['bounceOut'](x, d - t, 0, c, d) + b;
	},
	bounceOut: function(x, t, b, c, d) {
		if ((t /= d) < (1 / 2.75)) {
			return c * (7.5625 * t * t) + b;
		} else if (t < (2 / 2.75)) {
			return c * (7.5625 * (t -= (1.5 / 2.75)) * t + 0.75) + b;
		} else if (t < (2.5 / 2.75)) {
			return c * (7.5625 * (t -= (2.25 / 2.75)) * t + 0.9375) + b;
		}
		return c * (7.5625 * (t -= (2.625 / 2.75)) * t + 0.984375) + b;
	},
	bounceBoth: function(x, t, b, c, d) {
		if (t < d / 2) {
			return this['bounceIn'](x, t * 2, 0, c, d) * 0.5 + b;
		}
		return this['bounceOut'](x, t * 2 - d, 0, c, d) * 0.5 + c * 0.5 + b;
	}

});
